Since the original EXE file remains unaltered, CRC programs cannot detect this virus having infected a system.
Cyclic redundancy check bits: The last 16 bits contain an error detection code computed over the previous bits of the channel.
When hex dumps are intended to be manually entered into a computer, such as was the case with print magazine articles of home computer era a checksum byte (or two) would be added at the end of each row, commonly calculated as simple 256 modulo of sum of all values in the row or a more sophisticated CRC.
Cyclic redundancy check | Forum check | Cyclic guanosine monophosphate | Cyclic adenosine monophosphate | Check Point | Check My Brain | Check Yes Juliet | check | traveler's check | Tartan Check | Reality Check | reality check | Occurs check | Cyclic ketogenic diet | cyclic guanosine monophosphate | Cyclic group | cyclic group | Cyclic Delay Diversity | Cyclic delay diversity | cyclic | Cross-check | Check valve | Check Please | check (fabric) | Check card | cashier's check |
Physical sectors are actually larger than 512 bytes, as in addition to the 512 byte data field they include a sector identifier field, CRC bytes (in some cases error correction bytes) and gaps between the fields.
Data fidelity is ensured by a 32-bit cyclic redundancy check in each compressed data block using the Koopman polynomial (0xEB31D82E), which has a Hamming distance of from 4 to 114 kbits.